Henry Van Schaack was born in Kinderhook in 1733. He was the eldest son of Kinderhook merchant Cornelis Van Schaack and his wife, Albany native Lydia Van Dyck. At age 14, he was apprenticed to a New York City countinghouse.

The young man was a fur trader who ranged far into the Indian country where he forged business relationships with British officials including Hitchen Holland - his future father-in-law, and William Johnson. He married spinster Jane Holland in 1760. Their only child was born the following year.

During the Seven Years War, he was an officer in a New York Regiment - serving with distinction at Lake George and Niagara. He also held a number of administrative positions within the New York forces.

Wartime service recommended him for political patronage. He served as Albany
postmaster from 1757 to 1771. During that time, he settled in Albany -
ultimately taking over the farm located
south of the city and in possession of his ailing father in law. He joined
St. Peter's Anglican church although
he also supported the Albany Dutch church. During that time, he was emerging
as an Albany-based conduit for goods and products between London and the
Great Lakes outposts. His relationship with William Johnson merchant proved
mutually advantageous! He also accompanied John
Bradstreet on his expedition against the Indians in 1764.

However, in 1765, he was suspected of applying for the position of Stamp Tax collector. Early in 1766, that possibility occasioned quite a reaction from his Albany neighbors who came together as " sons of liberty" to denounce the Stamp Act and anyone who would seek to enforce it. Van Schaack was quick to explain himself in a letter to the provincial attorney general.

By 1770, he had left Albany and returned to the place of his birth. He served Kinderhook as a justice of the peace and as supervisor. In 1775, he was elected to the Albany County committee of correspondence from Kinderhook. However, before long he was under suspicion for anti-Revolutionary sentiments. He was examined, arrested, confined to the Tory jail, and ordered banished to Connecticut. But in October 1776, he was permitted to return to Kinderhook to care for his gravely ill father. Following his father's death, he was ordered to Connecticut.

He made his way to Great Barrington and, by the end of the war, to Pittsfield where he built a landmark home. He lived in Pittsfield for more than two decades as a gentleman farmer and magistrate. He was a prominent western Massachusetts Federalist.

Opposition to the stamp act still continued. In January, a committee from the Sons of Liberty waited upon six persons in Albany and requested them to take an oath that they would not accept the office of stamp distributor. All but Henry Van Schaack, the Albany post master, having complied, the mob went to the latter's house, a little below the city, broke the windows, furniture, and the piazza, and taking his pleasure sleigh into town consumed it in a bonfire, Alarmed at these demonstrations, Van Schaack took the required oath, and the mob dispersed.